Deep‐Intronic Variant in <scp> <i>RUNX2</i> </scp> Causing Pseudo‐Exon Inclusion in a Family With Cleidocranial Dysplasia

A deep-intronic single nucleotide variant in RUNX2 causes the characteristic clinical features of cleidocranial dysplasia (CCD) in a family via pseudo-exon inclusion into the mRNA. The pseudo-exon contains a premature stop codon and triggers mRNA decay, which results in RUNX2 haploinsufficiency, the known disease mechanism.